The increasing adoption of minimally invasive procedures in total joint arthroplasty is challenging current bone removal systems. As the envelope of the surgical site is contracted, the powered surgical tool has less volume in which to operate without damaging surrounding soft tissues or misshaping the bone. Current oscillating surgical saws have a large swing arc requiring a significant volume in which to operate. Current rotating burrs require less space but are more difficult to guide and navigate.
In situations where an oscillating saw is required to provide accurate guidance of bone resection and good bone apposition (i.e., an unguided burr has insufficient control to provide reproducible cuts), the design of the adjoining surfaces of the prostheses are constrained to be planar. This often results in more bone being removed than what is structurally required by the implant. Moreover, current orthopaedic procedures utilizing oscillating saws require the use of expensive jig systems (e.g., cutting blocks) to guide the position of the saw.
In an attempt to overcome one or more of these issues, a number of navigation systems for navigating a surgical burr have heretofore been developed. Such navigation systems have included active and passive robotic arms. In this approach, the arm either actively positions the burr in the correct position relative to the bone (irrespective of the surrounding soft tissue) or provides “passive” resistance to the burr being directed outside of the prescribed planned volume. In both cases, the burr is rigidly attached to a robotic jointed arm which may, in some cases, intrude into the sterile field and interrupt the surgeon's work flow. To date, adoption of such robotic technologies has been slow.